serial: sc16is7xx: compile I2C when REGMAP_I2C is module

drivers/tty/serial/sc16is7xx.c:1060:12: warning: 'sc16is7xx_probe' defined but not used [-Wunused-function]
 static int sc16is7xx_probe(struct device *dev,
            ^
drivers/tty/serial/sc16is7xx.c:1176:12: warning: 'sc16is7xx_remove' defined but not used [-Wunused-function]
 static int sc16is7xx_remove(struct device *dev)
            ^
drivers/tty/serial/sc16is7xx.c:1215:29: warning: 'regcfg' defined but not used [-Wunused-variable]
 static struct regmap_config regcfg = {
                             ^

Fixed these warnings by removing the `#ifdef CONFIG_REGMAP_I2C' around their
calls as this driver selects REGMAP_I2C in Kconfig. This part of driver just
didn't compile at all when REGMAP_I2C configured as module (CONFIG_REGMAP_I2C
is not defined, just CONFIG_REGMAP_I2C_MODULE).
Signed-off-by: Jan Moskyto Matejka <mq@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/sc16is7xx.c

@@ -1221,7 +1221,6 @@ static struct regmap_config regcfg = {
 	.precious_reg = sc16is7xx_regmap_precious,
 };
 
-#ifdef CONFIG_REGMAP_I2C
 static int sc16is7xx_i2c_probe(struct i2c_client *i2c,
 			       const struct i2c_device_id *id)
 {
@@ -1273,7 +1272,6 @@ static struct i2c_driver sc16is7xx_i2c_uart_driver = {
 };
 module_i2c_driver(sc16is7xx_i2c_uart_driver);
 MODULE_ALIAS("i2c:sc16is7xx");
-#endif
 
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Jon Ringle <jringle@gridpoint.com>");